Volcanic ice caves on Antarctica may host complex life

Volcanoes may provide life refuges when icy conditions prevail.

Antarctica is a relentlessly icy place, with estimates placing the amount of exposed land on the continent at less than one percent of its total surface. During glacial periods, the ice even expanded further—to the point where the edges of the continent's ice sheets extended far out into the ocean.

Yet somehow, life exists on Antarctica. And not just microbial life; there are insects and worms present, too. How have they survived the intensely icy conditions on the continent? A new paper suggests that volcanoes could be the key to life's persistence in our planet's deep south.

Seeking refuge

One of the researchers behind the new work, Ceridwen Fraser, has an ongoing interest in the idea of what are termed "refugia." These are locations where, due to quirks of geography and local climate, life can ride out otherwise harsh conditions that would extinguish it in the surrounding terrain. Once the conditions become more conducive to life—the glacial period ends, for example—the organisms in the refugia spread out and repopulate a wider area.

But where do you find a refugia on a continent like Antarctica, where conditions push life to its edges even under a warm, hospitable climate like today's? Fraser's past work suggests volcanoes might provide a more promising habitat. As in the ocean, volcanic vents could provide chemical energy that bacteria harvest to provide the base of a food chain. But in Antarctica, they can provide something equally critical: warmth. Unlike ocean vents, Antarctica's volcanic vents can be close enough to the surface to allow photosynthetic organisms to thrive.

In an earlier study, Fraser and some collaborators looked at maps of Antarctica's biodiversity. They found that the regions with the most species were centered on geologically active terrain. This supports the idea that volcanic activity creates refugia, allowing life to survive and spread back out when conditions allow.

In a follow-up to that work, Fraser has gone to Antarctica and obtained samples at the sites of volcanic vents. In some cases, these vents are ice free, allowing soil samples to be taken from the surface. In others, the vents are sub-glacial and have created an extensive network of ice caves. Past work at these sites has suggested the presence of microbes and fungi.

Life on ice

In this case, the researchers did a broad search for DNA that included looking for bacteria, plants, and animals. The exposed surface sites turned out to be rich in green algae, and these sites even had evidence of a more complex land plant, likely a moss (the DNA was a match to bryophytes). One animal showed up at one of the surface sites, based on DNA with a sequence closest to arachnids.

Many of these same organisms showed up in some of the ice cave systems the team looked at. Although six of the nine ice caves were devoid of DNA, one contained plants, and three of them contained some algae. The arachnid-like DNA showed up in one of the caves, as did DNA from a type of insect called a springtail. Two distantly related groups of worms also appeared to be present.

Overall, the team suggests that these are likely an underestimation of the biological diversity found in the caves, as they were only able to take samples from a small area inside the ice cave.

While geologically active regions can provide refugia during glacial periods, most individual vents have lifespans that are far shorter than the tens of thousands of years that ice dominates. But the researchers note that there are often complex networks of ice caves that link multiple vents. So, it's possible that cave networks could persist even as individual sources of steam and hot air come and go.

Ultimately, this is something that should probably be independently verified, since contamination can easily trip up the most careful of scientists when it comes to small quantities of DNA. And it would be good to confirm that there are actually living organisms down in these caves, since DNA could probably persist for many thousands of years in the icy conditions of Antarctica, long after the creature that carried it has died.

But the idea of a volcanic refugia is an important one, since it could provide a model for how life might survive elsewhere in our Solar System or how it made it through planet-wide freezes like the ones that happened in Earth's distant past. This work definitely seems to be worth a follow-up.

Does no one read H.P. Lovecraft anymore? This will not end well........

I had more of the Jules Verne or Edgar Rice Burroughs type of adventure story in mind. You know, lost worlds cut off for millennia, which have developed cultish societies in which priest-like figures restrict knowledge and the people worship shiny objects. Then, when outsiders arrive, their deranged leaders try to kill them, but ultimately end up destroying their own world. And the worrying thing is that whoever or whatever is down there presumably doesn't have such stories to warn them not to come out and trigger our doom.

Does no one read H.P. Lovecraft anymore? This will not end well........

I had more of the Jules Verne or Edgar Rice Burroughs type of adventure story in mind. You know, lost worlds cut off for millennia, which have developed cultish societies in which priest-like figures restrict knowledge and the people worship shiny objects. Then, when outsiders arrive, their deranged leaders try to kill them, but ultimately end up destroying their own world. And the worrying thing is that whoever or whatever is down there presumably doesn't have such stories to warn them not to come out and trigger our doom.

Whatever else you can say about those primitive societies, they seem to spend a goodly amount of time on fashion design and interpretive dancing.

Does no one read H.P. Lovecraft anymore? This will not end well........

That whistling out in the blizzard is surely just the wind. Those glimpses of membranous wings are surely a hallucination. Those curious pedapodal prints are surely not really tracks. Those red shining whipping around in the darkness are surely gas. Swamp gas. In Antarctica.

That multilimbed alien horror vivisecting you with crude surgical tools is probably just a nightmare.

One the John Muir's finest pieces--and one of my favorite pieces of writing--is about surviving a sudden snowstorm with the help of fumaroles. The whole thing is very much worth reading.

Quote:

Our discussions ended, Jerome made a dash from behind the lava block, and began forcing his way back some twenty or thirty yards to the Hot Springs against the wind flood, wavering and struggling as if caught in a torrent of water; and after watching in vain for any flaw in the storm that might be urged as a new argument for attempting the descent, I was compelled to follow. "Here," said Jerome, as we stood shivering in the midst of the hissing, sputtering fumaroles, "we shall be safe from frost." "Yes," said I, "we can lie in this mud and gravel, hot at least on one side; but how shall we protect our lungs from the acid gases? and how, after our clothing is saturated with melting snow, shall we be able to reach camp without freezing, even after the storm is over? We shall have to await the sunshine; and when will it come?

The patch of volcanic climate to which we committed ourselves has an area of about one-forth of an acre, but it was only about an eighth of an inch in thickness, because the scalding gas jets were shorn off close to the ground by the oversweeping flood of frost wind.

One the John Muir's finest pieces--and one of my favorite pieces of writing--is about surviving a sudden snowstorm with the help of fumaroles. The whole thing is very much worth reading.

Quote:

Our discussions ended, Jerome made a dash from behind the lava block, and began forcing his way back some twenty or thirty yards to the Hot Springs against the wind flood, wavering and struggling as if caught in a torrent of water; and after watching in vain for any flaw in the storm that might be urged as a new argument for attempting the descent, I was compelled to follow. "Here," said Jerome, as we stood shivering in the midst of the hissing, sputtering fumaroles, "we shall be safe from frost." "Yes," said I, "we can lie in this mud and gravel, hot at least on one side; but how shall we protect our lungs from the acid gases? and how, after our clothing is saturated with melting snow, shall we be able to reach camp without freezing, even after the storm is over? We shall have to await the sunshine; and when will it come?

The patch of volcanic climate to which we committed ourselves has an area of about one-forth of an acre, but it was only about an eighth of an inch in thickness, because the scalding gas jets were shorn off close to the ground by the oversweeping flood of frost wind.

Btw, have you ever listened to Richard Strauss' tone poem, Eine Alpensinfonie ('An Alpine Symphony', Op. 64)? You'll need to invest 45-50 minutes to listen to it, but it captures a day in the mountains perfectly.

"Yet somehow, life exists on Antarctica. And not just microbial life; there are insects and worms present, too."

And advanced multicellular life. Penguins have been native to Antarctica for many millions of years.

Hey all,I worked at McMurdo a few times. Which is right next door to Mt Erebus. This group almost certainly was supported by McMurdo and USAP even if they were from another country.

What I find fascinating is how bad the United States Antarctic program is at marketing itself. USAP should be like NASA, but last time I checked, their website didn't even have a mobile version. And all the information on it was not geared towards the public.

Also, the furthest south point of land above the ice line in Antarctica was found to have microbial life on it. Skuas are bad mofo birds that have even been spotted at the South Pole. (South pole is approx 900miles from nearest coast)

Btw, have you ever listened to Richard Strauss' tone poem, Eine Alpensinfonie ('An Alpine Symphony', Op. 64)? You'll need to invest 45-50 minutes to listen to it, but it captures a day in the mountains perfectly.

There are several kinds of ecosystems in Antarctica. Photosynthetic plants and lichens inhabit the clear ground, cyanos and algae thrive inside the ice sheet and ice caves and there are vibrant ecosystems in the subglacial lakes. It seems that volcanoes support some of these ecosystems but they are, by no means, required for *all* life on the continent. Antarctic organisms are highly adapted and for some of them "cool" conditions are potentially deadly, so volcanoes can only support a portion of antarctic life. Whatever the significance of the "refugia' is, it can't be universal for all of the continent.

Sometimes people think that only "exotic" lifeforms can survive the Antarctic, which is not the case. The sole Antarctic insect, Belgica Antarctica, survives by tunneling at merely one cm undergound, where the temperature is a stable 0 to -2 C all year long. Its larvae live for two years (required in order to accumulate nutrients in a very nutrient poor environment), while the adult form only lasts a couple of weeks. Otherwise it's not that an exotic organism for such a demanding environment. It's a celebrated case of life modifying it's behavior rather than overhauling its biochemistry in order to survive.